Preheat the oven to 350ºF. Spray a 9×13 casserole dish with cooking spray to prevent sticking. Set the dish aside while you prepare the ingredients.

In a large skillet over medium heat, cook the ground beef and sweet Italian sausage together until fully browned, breaking them up as they cook. Drain and discard any excess fat. Add the minced garlic and the prepared spaghetti sauce to the meat mixture. If your sauce is very thick, you may add up to 1/4 cup of water at this stage to loosen it. Simmer everything together for about 5 minutes to blend the flavors, then remove from heat.

In a large bowl, combine the ricotta cheese (or cottage cheese), 2 cups of shredded mozzarella cheese, eggs, 1/2 cup grated Parmesan cheese, dried (or fresh) parsley, salt, and black pepper. Mix well until the ingredients are evenly incorporated and creamy. I like to use fresh parsley for a burst of flavor, but dried works great too!

To assemble, spread about 3/4 cup of meat sauce (from Step 2) evenly over the bottom of the prepared baking dish. Layer 3 uncooked lasagna noodles over the sauce. Spoon and spread 1/3 of the cheese mixture (from Step 3) evenly over the noodles, then top with 1/4 of the remaining meat sauce. Repeat these layers two more times—noodles, cheese mixture, then sauce. Finish with a final layer of noodles (for a total of 12 noodles), cover with all the remaining sauce, then sprinkle with the remaining 1 cup of shredded mozzarella cheese and 1/4 cup of grated Parmesan cheese. If your sauce is thick, pour 1/4 cup water along the edges of the pan to help cook the noodles.

Spray a sheet of aluminum foil with cooking spray and cover the baking dish with the foil, sprayed side down, to prevent the cheese from sticking. Bake in the preheated oven for 50 minutes. Then, remove the foil and bake uncovered for an additional 10 minutes, or until the cheese on top is melted and golden. For a crispier top, you can broil it for a couple of minutes at the end if you like!

Remove the lasagna from the oven and let it stand for 10 minutes before slicing. This resting period helps the layers set, making serving much easier and tidier. I always find that waiting a few minutes before cutting yields perfect slices.